Clearly what happened in Nottingham was a freak occurrence. These are bleak times on the high street, and yes, there had been layoffs recently at HMV and Clinton Cards. But when Costa Coffee advertised for three full-time and five part-time baristas to staff a new shop in the Mapperley area of the city, the company never could have imagined it would get 1,701 applicants in two months, some with 10 to 15 years' experience in retail behind them. "It just shows how hard times are these days but also how popular an employer Costa is," said area manager Sham Ramparia, to nobody's surprise. Even so, he might be on to something. Something sparkly clings to that word "barista". There's some special cachet there.

This must surprise Italians. Because in Italy, where the word originates, it means just "bartender", fresh coffee being available at most Italian bars, as alcohol generally is in French cafes. In this country, where we're rather purposeful about our drinking, we like to separate our alcoholic and our caffeinated leisure time. And though coffee shops are not in the least bit new to Britain – the city of London grew out of them in the 17th century – we have never respected the drink enough to put a name to the people who sell it. Unlike the publicans, landlords, barmaids, barmen, sommeliers, wine waiters, even the mixologists, who kindly make us drunk.

The tremendous growth of the coffee chains has changed all this. Today, the coffee shop market in the UK is worth 10 times what it was in 1997, with 15,273 outlets currently estimated to be doing business. As they have joined our daily lives, so has a new kind of expert: the barista. While bartenders just pull a pint of someone else's beer or wine into a glass and hand it to you, a barista actually makes different drinks before your eyes, and through a process you couldn't replicate – at least not if there's any fancy milk involved.

But what makes this job so desirable? It's certainly not the money. Even a fully qualified "barista maestro" responsible for training junior baristas at a London branch of Costa Coffee earns a maximum of £7.15 per hour (plus some bonuses and incentives), compared with the £8.55 estimated by the Greater London Authority as a living wage (or £7.45 elsewhere). At Starbucks it's a maximum of £7.81 per hour after a three-month qualifying period (plus some shares). At Pret a Manger, it's a little better. There, the title of barista, with its black apron, is given only to people who pass a test at the end of a 12-week period. After this, if they earn their £1 per hour bonus every week (and they do most weeks), they are paid at least £8.05/hour. Some may rise to managerial positions and earn more, but no barista in a major coffee chain gets even to within 10 grand of the national average annual wage, which is £26,500.

At the chains, new baristas learn on the job, mostly by watching others and being watched, like in any shop. When they reach a higher level, such as a barista maestro, they go for more formal training sessions. But these are not stringent, drawn-out periods of study. An advanced course with one of the leading training providers, such as Coffee Community, Barista BarBar or the London School of Coffee, lasts just one day. Many simpler courses take only a few hours, less time than it takes to get the basic food-hygiene certificate. Besides, many of the skills of coffee-making, such as choosing the beans, the coarseness of the grind, the heat and pressure of the water, are often necessarily taken out of baristas' control at the big chains.

And sometimes, in practice, things can be very desultory indeed. "You are trained on the job, and often by people who have only recently been trained themselves," says one former Costa Coffee employee who we'll call Helen. "Managers showed little or no interest in your progress … They would often be disappointed in the level of training that the baristas had, but made no effort to train them themselves. I taught myself the majority of what I needed to know."

At the age of 17, Helen believes she was also the oldest employee in the branch besides the manager. "Very few of the staff members cared about serving good coffee either," she says. "We are given bags of the coffee, we grind it, we make drinks from it and that's it. When there's a queue of people out the door, as is the case most weekends, quality is not something most employees are thinking about. If it's drinkable and looks OK, it's serviceable."

So is glamorising this type of work with the word "barista" the coffee chains' true masterstroke? Well, for the mostly young people who do it, making lots of money is not always the point. Bar work or jobs in restaurants and record shops have been employment staples for many years, yet they have never been well paid. When I worked shifts behind bars in my late teens and early 20s, I was living either at home or in student accommodation. I wasn't trying to house a family. Coffee shops can even employ people under the age of 18 on just £3.68 per hour if they choose, although most don't.

Erinn Kerr was only 18 when she got her first job at a Starbucks in Belfast. "I was going to be there all the time anyway, so I might as well be paid," she says. And she went on to have a great time, even if she remembers having just two days' on-the-job training. "I absolutely loved it, honestly. It was a great job," she says. In this respect, the friendly atmosphere, the chance to chat to customers and the regular staff tastings of new types of beans were all important. And despite the highly automated system at Starbucks, she still took a keen interest in getting the right milk density for different drinks, pouring the espresso shot into the milk quickly enough, and generally trying to do a good job. "I have become a massive coffee snob," she says.

For Kerr, much of the love went out of the work when she moved to Newcastle and found herself working at Starbucks franchises in her student union and in the train station, where she says standards were not as high. And for people like Kerr, and many of those – mostly in the independent shops – who are more serious about coffee, a whole barista culture has grown up.

There is Barista Magazine. There is the World Barista Championship. There is a whole look, with tattoos and trendy clothes, and an attitude – an odd combination of the laidback and the intensely serious – that marks out the career barista. "The image of the barista has almost become a fashion statement," says Paul Meikley-Janney, a judge at the World Barista Championship and managing director of Coffee Community, which works with roasters, machine manufacturers and coffee shops, including Costa and SSP. "If you looked at 50 chefs in a room with 50 civilians, all in street clothes, you wouldn't be able to tell the difference. If you did the same with the top barista world, you would spot the baristas."

In short, Costa, Starbucks, Caffe Nero, Pret-a-Manger and the rest may offer a rather watery version of the barista lifestyle, but that lifestyle is real and admired. As is the drink. The growth of proper coffee's popularity in Britain continues to amaze. Twice as many people go into a coffee shop each day now, compared with 2009. Big companies such as Tesco and Greggs are still piling in, and the size of the market as a whole is expected to grow by 25% in the next five years.

Yet this is only one of two big changes: the other being the long-term decline of pubs, and of alcohol consumption generally. What this one word "barista" captures, in an intense shot, is a shift away from drunken revelry. In this new world, less brave but maybe more mature, the person who controls the steamer calls the tune.